#pragma once #include namespace DB { class IDisk; using DiskPtr = std::shared_ptr; /// Helper class, that receives file descriptor and does fsync for it in destructor. /// It's used to keep descriptor open, while doing some operations with it, and do fsync at the end. /// Guaranties of sequence 'close-reopen-fsync' may depend on kernel version. /// Source: linux-fsdevel mailing-list https://marc.info/?l=linux-fsdevel&m=152535409207496 class LocalDirectorySyncGuard final : public ISyncGuard { public: /// NOTE: If you have already opened descriptor, it's preferred to use /// this constructor instead of constructor with path. explicit LocalDirectorySyncGuard(int fd_) : fd(fd_) {} explicit LocalDirectorySyncGuard(const String & full_path); ~LocalDirectorySyncGuard() override; private: int fd = -1; }; }